200+ Interview Questions and Answers

tmap is used to transform data in Talend, tjoin is used to join data. There are different types of connections, truncate and delete are different ways to remove data from a table. ETL stands for Extract, Transform, Load. Triggers are database objects that are automatically executed in response to certain events. There are different types of joins.

• tmap is used for data transformation in Talend

• tjoin is used for joining data in Talend

• Types of connections include database connect...read more

The @RestController annotation is a specialized version of the @Controller annotation in Spring MVC.

• The @Controller annotation is used to define a controller class in Spring MVC.

• The @RestController annotation is used to define a RESTful web service controller.

• The @RestController annotation is a combination of @Controller and @ResponseBody annotations.

• The @Controller annotation returns a view while the @RestController annotation returns data in JSON or XML format.

• Example: @Con...read more

The gold rate has been fluctuating in the past week.

• Gold rate increased on Monday and Tuesday, but decreased on Wednesday and Thursday.

• On Friday, the rate remained stable.

• Overall, there has been a slight decrease in the gold rate over the past week.

Data from an Excel sheet can be brought into Databricks using the read method in Databricks.

• Use the read method in Databricks to read the Excel file.

• Specify the file path and format (e.g. 'xlsx') when using the read method.

• Transform the data as needed using Databricks functions and libraries.

• Example: df = spark.read.format('com.crealytics.spark.excel').option('useHeader', 'true').load('file.xlsx')

Hibernate get() returns object by id, load() returns proxy object until accessed.

• get() method returns the object from the database by its id.

• load() method returns a proxy object until it is accessed, then it loads the object from the database.

• get() method returns null if the object is not found in the database, while load() method throws an exception.

• get() method is eager loading, while load() method is lazy loading.

Agile methodologies are preferred for their flexibility, collaboration, and ability to adapt to changing requirements.

• Agile methodologies prioritize individuals and interactions over processes and tools.

• They emphasize working software over comprehensive documentation.

• Agile allows for frequent iterations and feedback, leading to quicker delivery of value to customers.

• Scrum, Kanban, and Extreme Programming (XP) are popular agile frameworks.

• Agile promotes continuous improvement ...read more

To find the second largest number in an array using JavaScript, sort the array in descending order and return the element at index 1.

• Sort the array in descending order using the sort() method.

• Access the element at index 1 to get the second largest number.

ES6 is the newer version of JavaScript with added features like arrow functions, classes, and let/const declarations.

• ES5 is the fifth version of ECMAScript, released in 2009.

• ES6, also known as ECMAScript 2015, introduced new features like arrow functions, classes, let/const declarations, template literals, and spread/rest operators.

• ES6 also added features like default parameter values, destructuring assignments, and promises.

• ES6 modules allow for better organization and encap...read more

Handle git merge conflicts by resolving conflicts manually or using tools like git mergetool.

• Manually resolve conflicts by editing the conflicting files in text editor

• Use 'git status' to see which files have conflicts

• Use 'git diff' to see the conflicting changes

• Use 'git mergetool' to open a visual merge tool to resolve conflicts

• After resolving conflicts, add the changes and commit the merge

I would use a List collection and sort by Price in ascending order.

• Use List collection for dynamic size and easy sorting

• Sort by Price in ascending order using built-in sorting methods

• Example: List products = new List(); products.Sort((x, y) => x.Price.CompareTo(y.Price));

React lifecycle consists of three main stages: Mounting, Updating, and Unmounting.

• Mounting: Component is created and inserted into the DOM.

• Updating: Component is re-rendered due to changes in props or state.

• Unmounting: Component is removed from the DOM.

• Examples: componentDidMount() is called during Mounting stage, componentDidUpdate() during Updating stage, and componentWillUnmount() during Unmounting stage.

I use various git commands like git clone, git pull, git push, git commit, git branch, git merge, etc.

• git clone - to clone a repository from a remote server

• git pull - to fetch and merge changes from a remote repository

• git push - to push changes to a remote repository

• git commit - to save changes to the local repository

• git branch - to create, list, delete, or manipulate branches

• git merge - to merge changes from one branch to another

Activities include ETL processes, data migration, data synchronization, and data replication.

• ETL (Extract, Transform, Load) processes

• Data migration

• Data synchronization

• Data replication

Talend is popular due to its open-source nature, ease of use, and ability to integrate with various systems.

• Talend is open-source, making it accessible to a wide range of users.

• It has a user-friendly interface, allowing developers to easily create and manage data integration workflows.

• Talend can integrate with various systems, including cloud-based platforms like AWS and Azure.

• It offers a wide range of connectors and components, making it versatile and adaptable to different ...read more

Talend is an ETL tool used for data integration. Jobs are workflows created in Talend to perform specific tasks. Components are pre-built functions used in jobs.

• Jobs are created in Talend to perform specific tasks such as data extraction, transformation, and loading.

• Components are pre-built functions that can be used in jobs to perform specific actions such as reading data from a file or database, transforming data, and writing data to a file or database.

• Talend provides a wid...read more

Domain is a collection of data elements, select statement retrieves specific data, value tables store data values, BDC is used for data transfer, smart forms are advanced form creation tools.

• Domain is a collection of data elements defining the characteristics of a field.

• Select statement retrieves specific data from a database table based on specified criteria.

• Select all statement retrieves all data from a database table.

• Value tables store data values for selection in dropdown...read more

Use Python to print the last 10 dates from today in the specified format.

• Get the current date using the datetime module in Python.

• Loop through the last 10 days using a for loop and timedelta to subtract one day at a time.

• Format each date as 'day month year' using strftime method.

• Store each formatted date in an array of strings.

Use SQL query to retrieve employees with birthdays and send emails to them.

• Write a SQL query to retrieve employees with birthdays from the database

• Use a programming language like Python to send emails to the retrieved employees

• Ensure the email content includes birthday wishes and any relevant information

Integrating multiple legacy systems with modern cloud-based applications.

• Developing custom APIs to bridge the gap between different systems

• Handling data transformation and mapping between incompatible formats

• Ensuring data security and compliance during integration

• Resolving performance issues and optimizing data flow

• Collaborating with various teams to understand system requirements and constraints

To resolve performance issues while consuming details from API in Pega, optimize API calls, use caching, and analyze network and server performance.

• Optimize API calls by reducing unnecessary data retrieval and processing

• Implement caching mechanisms to store frequently accessed data locally

• Analyze network and server performance to identify bottlenecks and optimize accordingly

To get the assignment details of the operator for a specific access group in Pega, you can use the OOTB activity 'pxRetrieveAssignmentsForOperator'.

• Use the OOTB activity 'pxRetrieveAssignmentsForOperator' to retrieve assignment details for a specific operator and access group.

• Pass the operator ID and access group name as parameters to the activity.

• The activity will return a list of assignments for the specified operator and access group.

Functional components are simpler, more concise, easier to read, and promote reusability.

• Functional components are simpler and more concise compared to class components.

• Functional components use less code and are easier to read and maintain.

• Functional components promote reusability through the use of hooks.

• Functional components are easier to test and debug.

• Functional components support the use of React hooks for managing state and side effects.

useCallback is used to memoize functions, while useMemo is used to memoize values.

• useCallback is used to memoize functions to prevent unnecessary re-renders.

• useMemo is used to memoize values to prevent expensive calculations.

• Both useCallback and useMemo accept a dependency array to determine when to recalculate the memoized value.

Jira is a project management tool used for tracking issues, managing tasks, and organizing workflows.

• Jira is commonly used in software development teams to track bugs, tasks, and user stories.

• It allows users to create and prioritize tasks, assign them to team members, and track progress.

• Jira also provides reporting and dashboard features to monitor project status and performance.

• Integration with other tools like Confluence, Bitbucket, and Slack makes collaboration easier.

ERP is a broader category of software that manages business processes, while S4Hana is a specific ERP solution developed by SAP.

• ERP is a broader category of software that integrates various business functions like finance, HR, supply chain, etc., while S4Hana is a specific ERP solution developed by SAP.

• S4Hana is built on SAP's in-memory platform, HANA, which allows for real-time data processing and analytics, while traditional ERPs may not have this capability.

• S4Hana offers a...read more

Manageable code is well-structured, organized, and easy to maintain, while unmanageable code is messy, hard to understand, and prone to errors.

• Manageable code follows best practices and design patterns, making it easier to read and maintain.

• Unmanageable code lacks structure, consistency, and documentation, making it difficult to work with.

• Examples of manageable code include well-commented classes and methods, consistent naming conventions, and modular architecture.

• Examples of...read more

Merge two arrays by sorting them and using minimum loops

• Sort both arrays individually

• Merge the two sorted arrays by comparing elements and inserting them in the correct position

• Use only one loop to iterate through both arrays simultaneously

Position absolute and position relative are CSS properties used to position elements on a webpage.

• Position absolute positions an element relative to its closest positioned ancestor.

• Position relative positions an element relative to its normal position on the webpage.

• Position absolute elements are taken out of the normal flow of the document.

• Position relative elements are still in the normal flow but can be moved from their original position.

Design patterns used in project help in organizing code and solving common problems efficiently.

• Singleton pattern - ensures a class has only one instance and provides a global point of access.

• Factory pattern - creates objects without specifying the exact class to create.

• Observer pattern - defines a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically.

• Strategy pattern - defines a family of algor...read more

Stored Procedures are precompiled SQL queries stored in the database for reuse. Optimization involves reducing execution time.

• Stored Procedures are precompiled SQL queries stored in the database for reuse.

• They can improve performance by reducing network traffic and improving security.

• Optimization techniques include using proper indexing, minimizing data manipulation within the SP, and avoiding unnecessary loops.

• Example: CREATE PROCEDURE GetEmployeeDetails AS SELECT * FROM Emp...read more

The coding round was challenging but I managed to solve all the problems using a systematic approach.

• I started by carefully reading and understanding the problem statement.

• I broke down the problem into smaller subproblems to tackle them individually.

• I used pseudocode to plan out my solution before writing actual code.

• I tested my code thoroughly to ensure it was working correctly.

• I optimized my code for efficiency and readability.

A do while loop is a control flow statement that executes a block of code at least once, and then repeatedly executes the block as long as a specified condition is true.

• Initialize a variable outside the loop

• Use the do keyword to start the loop

• Write the code block to be executed inside the loop

• Use the while keyword followed by the condition to continue the loop

Lambda is a serverless computing service provided by AWS, while EC2 is a virtual server service also provided by AWS.

• Lambda is serverless, meaning you don't have to provision or manage servers like you do with EC2

• Lambda functions are event-driven and only run when triggered, while EC2 instances are always running

• Lambda is more cost-effective for short, infrequent tasks, while EC2 is better for long-running, consistent workloads

Java code using stream api to retrieve second highest salary

• Use stream to sort salaries in descending order

• Skip the first highest salary and retrieve the second highest

Volatile keyword is used to indicate that a variable's value can be changed unexpectedly by external factors.

• Volatile keyword is used in multithreaded programming to ensure that the variable's value is always read from memory and not from cache.

• It is also used in embedded systems programming to indicate that the variable's value can be changed by hardware interrupts.

• Example: volatile int count = 0; // variable can be changed by external factors

• Example: int count = 0; // varia...read more

The gold rate today varies depending on the location and currency. Please specify the location and currency for an accurate answer.

• Gold rate varies by location and currency

• Check with local jeweler or online sources for accurate rates

• Factors such as demand, supply, and global economic conditions affect gold rates

connectedCallback and renderedCallback are lifecycle hooks in Lightning Web Components.

• connectedCallback is called when a component is inserted into the DOM. Use it to perform one-time setup tasks.

• renderedCallback is called after the component's elements are rendered. Use it to interact with the DOM after rendering.

Application developers benefit from job flexibility, high demand, and competitive salaries.

• Job flexibility allows developers to work remotely or on a flexible schedule

• High demand for skilled developers ensures job security and opportunities for growth

• Competitive salaries in the tech industry offer financial stability and potential for advancement

Python is a high-level programming language known for its simplicity and readability.

• Easy to learn and use

• Extensive standard library

• Versatile - used for web development, data analysis, artificial intelligence, etc.

• Cross-platform compatibility

• Strong community support

DDIC tables are used in SAP systems to store metadata and data dictionary information.

• Transparent tables: store application data and have a one-to-one relationship with the database table

• Pooled tables: store control data and have a one-to-many relationship with the database table

• Cluster tables: store data from multiple tables with a one-to-many relationship

• View tables: virtual tables that display data from other tables without storing it physically

Communication between Parent to child and viceversa involves sharing information, emotions, and support.

• Effective communication involves active listening and clear expression of thoughts and feelings.

• Parents should provide guidance, support, and encouragement to their children.

• Children should feel comfortable sharing their thoughts and feelings with their parents.

• Open and honest communication helps build trust and strengthen the parent-child relationship.

String is immutable, StringBuffer is mutable in Java.

• String is immutable, meaning once created, it cannot be changed. StringBuffer is mutable, allowing for modifications.

• StringBuffer is synchronized, making it thread-safe. String is not synchronized.

• StringBuffer is more efficient for concatenating multiple strings due to mutability.

• Example: String str = "Hello"; StringBuffer sb = new StringBuffer("Hello");

Checked exceptions are checked at compile time, while unchecked exceptions are not.

• Checked exceptions must be either caught or declared in the method signature using 'throws' keyword

• Unchecked exceptions do not need to be caught or declared

• Examples of checked exceptions: IOException, SQLException

• Examples of unchecked exceptions: NullPointerException, ArrayIndexOutOfBoundsException

I am proficient in Java, Python, C++, and JavaScript.

• Java

• Python

• C++

• JavaScript

Validation in LWC refers to ensuring that user input meets specified criteria before submission.

• Use HTML5 form validation attributes like required, pattern, min, max, etc.

• Implement custom validation logic in JavaScript using imperative or declarative approach.

• Display error messages to users for invalid input.

Transient keyword is used in Java to indicate that a variable should not be serialized.

• Transient keyword is used with variables to exclude them from serialization process.

• It is used to mark a variable as non-persistent.

• Transient variables are not saved during serialization and are initialized to default value during deserialization.

• Example: private transient int age; // age will not be serialized

For loop is used when the number of iterations is known, while loop is used when the condition is true.

• For loop is used when the number of iterations is known beforehand.

• While loop is used when the condition needs to be checked before each iteration.

• For loop is more concise and easier to read for simple iterations.

• While loop is more flexible and can handle complex conditions.

• Example: for(int i=0; i<5; i++) { //code }

• Example: while(condition) { //code }

Use bitwise XOR operation to swap two integers without a temp variable.

• Use XOR operation to swap two integers: a ^= b, b ^= a, a ^= b

• Example: int a = 5, b = 10; a ^= b; b ^= a; a ^= b; // Now a = 10, b = 5

To add an external server on Spring Boot, you can configure the server properties in the application.properties file.

• Define the server properties in the application.properties file, such as server.port, server.address, etc.

• Specify the external server details like host and port in the properties file.

• Use the @Value annotation to inject the server properties into your Spring Boot application.

• You can also use the @ConfigurationProperties annotation to bind the external server pr...read more

Custom queries in Spring Boot JPA can be written using @Query annotation in repository interface methods.

• Use @Query annotation in repository interface methods to write custom queries

• Specify the JPQL query in the value attribute of @Query annotation

• You can also use native SQL queries by setting nativeQuery attribute to true in @Query annotation

Release pipeline is for deploying code to production, build pipeline is for compiling code.

• Release pipeline is used for deploying code to production environment after successful testing.

• Build pipeline is used for compiling source code into executable code or artifacts.

• Release pipeline includes stages like Dev, Test, and Prod for deployment.

• Build pipeline includes tasks like compiling code, running tests, and packaging artifacts.

• Example: In Azure DevOps, you can create separat...read more

To call an overridden method, use the super keyword followed by the method name.

• Use 'super' keyword followed by the method name to call the overridden method.

• Example: super.methodName();

Program to remove duplicates in a string

• Create an empty array to store unique characters

• Iterate through each character in the string

• Check if the character is already in the array, if not add it

Polymorphism in CPP allows objects of different classes to be treated as objects of a common superclass.

• Polymorphism allows for functions to be called on objects of different classes through a common interface.

• There are two types of polymorphism in CPP: compile-time (function overloading, operator overloading) and runtime (virtual functions).

• Example: A base class 'Shape' with virtual function 'draw()' can have subclasses 'Circle' and 'Rectangle' that override 'draw()' to impl...read more

Exception handling is a mechanism to handle errors or exceptional situations in a program.

• It allows the program to gracefully handle unexpected situations without crashing.

• Exceptions can be caught and handled using try-catch blocks.

• Common exceptions include NullPointerException, ArrayIndexOutOfBoundsException, and IOException.

• Exception handling helps in improving the robustness and reliability of the software.

Broadcast variable in Spark is a read-only variable that is cached on each machine rather than shipping a copy of it with tasks.

• Broadcast variables are used to efficiently distribute large read-only data to all worker nodes in Spark applications.

• They are cached in serialized form and can be used across multiple stages of a Spark job.

• Broadcast variables help in reducing the network overhead and improving the performance of Spark applications.

• Example: broadcasting a lookup tabl...read more

Angular is a popular front-end framework for building dynamic web applications.

• Angular is maintained by Google and is based on TypeScript.

• It allows for the creation of single-page applications with a modular and component-based architecture.

• Angular provides features like data binding, dependency injection, and routing.

• It has a large community and ecosystem with many third-party libraries and tools available.

• Angular is often chosen for its performance, scalability, and develop...read more

Functional interfaces in Java are interfaces with only one abstract method, allowing lambda expressions to be used for implementation.

• Functional interfaces can have multiple default methods but only one abstract method.

• They can be implemented using lambda expressions.

• Examples include java.lang.Runnable, java.util.Comparator, and java.util.function.Predicate.

SQL is a relational database management system, while NoSQL is a non-relational database management system. Springboot annotations are used for configuration in Spring applications.

• SQL is table-based, with a predefined schema, while NoSQL is document, key-value, wide-column, or graph-based, with a dynamic schema.

• SQL is best suited for complex queries and transactions, while NoSQL is better for hierarchical data storage and real-time web applications.

• Springboot annotations lik...read more

To deactivate a trigger in production, you can use the ALTER TRIGGER statement to disable the trigger.

• Use the ALTER TRIGGER statement with the DISABLE option to deactivate the trigger.

• Make sure to test the trigger deactivation in a non-production environment before applying it to production.

• Document the trigger deactivation process for future reference and troubleshooting.

Shipping involves sending individual items to customers, while consolidated shipping combines multiple items into one shipment.

• Shipping involves sending individual items to customers separately

• Consolidated shipping combines multiple items into one shipment for cost efficiency

• Consolidated shipping is often used for bulk orders or shipments to the same location

• Example: Shipping a single book to a customer vs. consolidating multiple books into one shipment for a bookstore

Talend and Pentaho are both open-source data integration tools, but Talend is more user-friendly while Pentaho has better reporting capabilities.

• Talend has a drag-and-drop interface and a large library of pre-built components, making it easier for non-technical users to create data integration workflows.

• Pentaho has a more robust reporting engine and better visualization capabilities, making it a better choice for business intelligence and analytics.

• Both tools support a wide r...read more

Future methods are used for asynchronous processing within the same transaction, while Queueable is used for asynchronous processing outside the transaction.

• Future methods are limited to 50 method calls per transaction, while Queueable has no such limit.

• Future methods are queued in the order they are called, while Queueable jobs can be prioritized.

• Future methods are executed in a separate thread, while Queueable jobs are executed in a separate transaction.

• Future methods are u...read more

Key points for outbound integration

• Understand the data format and structure of the outbound system

• Ensure secure transmission of data

• Implement error handling and logging mechanisms

• Consider scalability and performance of the integration

• Test thoroughly to ensure data accuracy and reliability

Code to remove duplicate letters from a string

• Iterate through the string and keep track of seen characters

• Use a set to store unique characters

• Join the set elements to form the final string

Code is deployed to production using automated deployment pipelines and version control systems.

• Use automated deployment pipelines to push code changes to production servers

• Utilize version control systems like Git to manage code changes and track versions

• Perform testing in staging environments before deploying to production

• Implement continuous integration and continuous deployment practices for efficient deployment process

Slowly changing dimensions are dimensions in a data warehouse that change slowly over time.

• Slowly changing dimensions are used to track historical changes in data over time.

• There are three types of slowly changing dimensions: Type 1, Type 2, and Type 3.

• Type 1: Overwrites old data with new data, losing historical information.

• Type 2: Creates a new record for each change, preserving historical data.

• Type 3: Creates a new field to store the most recent change, keeping some histori...read more

I have worked on SAP ECC 6.0 and SAP S/4HANA.

• Worked on SAP ECC 6.0 for 3 years in previous job

• Currently working on SAP S/4HANA implementation project

• Experience with customizing and developing ABAP programs in SAP

Spring Boot provides rapid application development, simplified configuration, embedded servers, and production-ready features.

• Rapid application development with minimal configuration

• Embedded servers for easy deployment

• Production-ready features like metrics, health checks, and externalized configuration

• Simplified dependency management with Spring Boot Starter projects

Reverse a string without using built-in methods

• Create an empty string to store the reversed string

• Iterate through the input string from end to start and append each character to the new string

• Return the reversed string as the output

Use SQL query with ORDER BY and LIMIT to find 2nd or nth highest salary

• Use ORDER BY clause to sort salaries in descending order

• Use LIMIT to specify the number of rows to return

• For 2nd highest salary: SELECT salary FROM employees ORDER BY salary DESC LIMIT 1, 1

• For nth highest salary: SELECT salary FROM employees ORDER BY salary DESC LIMIT n-1, 1

Tcode for BADI is SE18. To find a BADI, use transaction code SE18 and enter the BADI name or filter by application area.

• Tcode for BADI is SE18

• To find a BADI, use transaction code SE18

• Enter the BADI name or filter by application area

Tables store data in rows and columns, while stored procedures are precompiled SQL statements that can be executed.

• Tables store data in a structured format with rows and columns

• Stored procedures are precompiled SQL statements that can be executed

• Tables are used to store and organize data, while stored procedures are used to perform specific tasks or operations on the data

• Stored procedures can improve performance by reducing the amount of data sent between the application and ...read more

Configuration refers to the settings and options that determine how a software application behaves.

• Configuration includes parameters such as database connection details, API keys, and user preferences.

• It allows users to customize the behavior of the application without changing its code.

• Configuration files are commonly used to store settings in a structured format, such as JSON or XML.

Different part types refer to the various components or elements that make up a whole system or object.

• Hardware parts (e.g. CPU, RAM, motherboard)

• Software parts (e.g. modules, libraries)

• Mechanical parts (e.g. gears, screws)

• Electrical parts (e.g. resistors, capacitors)

Lambda function is an anonymous function in Python that can have any number of arguments, but can only have one expression.

• Lambda functions are defined using the lambda keyword.

• They are commonly used for small, one-time operations.

• Lambda functions can be used as arguments to higher-order functions like map, filter, and reduce.

• Example: add = lambda x, y: x + y

To redeclare a variable in VBA, you can simply use the Dim keyword followed by the variable name.

• Use the Dim keyword followed by the variable name to redeclare a variable in VBA.

• You can also use the ReDim statement to change the size of an array variable.

• Make sure to use the same data type when redeclaring a variable.

To copy a cell value using VBA, you can use the Value property of the Range object.

• Use the Range object to specify the cell you want to copy the value from.

• Access the Value property of the Range object to get the cell value.

• Assign the cell value to another cell or variable to copy it.

Java 8 introduced several new features including lambda expressions, functional interfaces, streams, and the new Date and Time API.

• Lambda expressions: Allow you to treat functionality as a method argument.

• Functional interfaces: Interfaces with a single abstract method, used for lambda expressions.

• Streams: Provide a way to work with sequences of elements.

• Date and Time API: Improved API for handling date and time operations.

Exception handling in Java involves try, catch, finally, and throw keywords.

• Use try block to enclose the code that may throw an exception

• Use catch block to handle the exception

• Use finally block to execute code after try/catch blocks

• Use throw keyword to manually throw an exception

Imputations are used in data analysis to fill in missing values with estimated values.

• Imputations are used when there are missing values in a dataset.

• Common methods of imputation include mean imputation, median imputation, and regression imputation.

• Imputations help to maintain the integrity of the dataset and ensure accurate analysis results.

HashMap is not thread-safe while ConcurrentHashMap is thread-safe.

• HashMap is not thread-safe and can lead to ConcurrentModificationException if modified while iterating.

• ConcurrentHashMap allows concurrent modifications without the need for external synchronization.

• ConcurrentHashMap uses separate locks for different segments, allowing multiple threads to read and write concurrently.

• ConcurrentHashMap is more suitable for high-concurrency scenarios compared to HashMap.

Request param is part of the URL path, while query param is part of the URL query string.

• Request param is used to pass data in the URL path, while query param is used to pass data in the URL query string.

• Request param is specified in the URL path after the endpoint, while query param is specified in the URL after a '?' and separated by '&'.

• Example of request param: /users/{id}, example of query param: /users?name=John&age=30

Spring is a framework for building Java applications, while Spring Boot is an extension that simplifies the setup and development process.

• Spring is a comprehensive framework for building Java applications, providing support for various modules like Spring MVC, Spring Security, and Spring Data.

• Spring Boot is an extension of the Spring framework that aims to simplify the setup and development of Spring applications by providing defaults and auto-configuration.

• Spring Boot includ...read more

Redux is a predictable state container for JavaScript apps. It helps manage the state of an application in a single immutable state tree.

• Redux is commonly used with React to manage the state of the application.

• To create a store in Redux, you need to use the createStore function from the Redux library.

• Example: const store = createStore(reducer);

Spark is a distributed computing framework for big data processing, partitioning is dividing data into chunks, and shuffling is the process of redistributing data across partitions.

• Spark is a fast and general-purpose cluster computing system.

• Partitioning in Spark involves dividing data into smaller chunks to distribute work across nodes.

• Shuffling in Spark is the process of redistributing data across partitions to perform operations like joins or aggregations.

• Partitioning and ...read more

Conditional rendering in LWC allows displaying or hiding elements based on specified conditions.

• Use if:true directive to conditionally render an element

• Use if:false directive to conditionally hide an element

• Use ternary operator in HTML template to conditionally render elements

State in React.js is used to store and manage component data that can change over time.

• State allows components to re-render when data changes

• State is used to manage user input, form data, and application state

• State is mutable and can be updated using setState() method

Drop, delete and truncate are SQL commands used to remove data from a table, but with different functionalities.

• DROP: Used to remove an entire table or database.

• DELETE: Used to remove specific rows from a table.

• TRUNCATE: Used to remove all rows from a table, but keeps the table structure.

• DROP and TRUNCATE are faster than DELETE as they do not log individual row deletions.

BigQuery is a cloud-based data warehouse that uses SQL-like queries, but with some key differences from traditional SQL databases.

• BigQuery is designed for large-scale data processing and analytics in the cloud.

• BigQuery uses a columnar storage format for faster query performance.

• BigQuery is fully managed and serverless, meaning users don't have to worry about infrastructure management.

• BigQuery supports nested and repeated fields, making it easier to work with semi-structured d...read more

git stash temporarily shelves changes in working directory

• Stashes changes in working directory

• Allows switching branches without committing changes

• Can apply stashed changes later

Authentication verifies the identity of a user, while authorization determines the access level of a user.

• Authentication confirms the user's identity through credentials like passwords or biometrics.

• Authorization controls what resources a user can access based on their authenticated identity.

• Example: Logging into a system with a username and password is authentication, while being able to view certain files based on user roles is authorization.

Job Scheduler is a software tool that schedules and automates tasks to be executed at specific times or intervals.

• Job Scheduler helps in automating repetitive tasks

• It can be used for scheduling backups, sending emails, running scripts, etc.

• It reduces manual effort and improves efficiency

• Examples include Cron, Windows Task Scheduler, and IBM Workload Scheduler

Output index refers to a specific position in a list or array, while output indexes refers to multiple positions in a list or array.

• Output index refers to a single position in a list or array, such as output[0].

• Output indexes refers to multiple positions in a list or array, such as output[0], output[1], output[2].

Use sorting or iteration to find the second largest integer in an array.

• Sort the array in descending order and return the second element.

• Iterate through the array and keep track of the largest and second largest integers.

• Handle edge cases like duplicates or empty arrays.

SOSL Injection is a type of injection attack that targets Salesforce Object Search Language queries.

• Use binding variables instead of concatenating user input into SOSL queries

• Validate and sanitize user input before using it in SOSL queries

• Limit the fields and objects that can be searched using SOSL to reduce the attack surface

Semantic tags are HTML tags that provide meaning to the content they enclose, helping search engines and screen readers understand the structure of a webpage.

• Semantic tags help improve SEO by providing context to search engines.

• They also improve accessibility for screen readers by clearly defining the structure of a webpage.

• Examples of semantic tags include

  ,

ConcurrentHashMap is a thread-safe version of HashMap in Java.

• ConcurrentHashMap allows multiple threads to read and write to the map concurrently without causing any data corruption.

• It achieves thread-safety by dividing the map into segments and locking only a portion of the map during write operations.

• ConcurrentHashMap is more efficient than using synchronized collections for concurrent access.

• Example: ConcurrentHashMap map = new ConcurrentHashMap<>();